1. Field of the Invention
The present invention relates to a speaker structure, especially to a retractable speaker structure for use in a vehicle.
2. Description of Related Art
At present, the mainframe of an audio/video equipment is mainly mounted in a panel at the front side of a driver's seat, and the speaker is mounted in a vehicle door or the panel; because the speaker has directivity relative to the user, the mounting location of the speaker plays an important role regarding to the entertaining effect; for allowing the speaker to provide an excellent performance, the speaker has to be protrudingly installed on the panel or the vehicle door, however, the above-mentioned arrangement would cause the speaker to be more likely to be damaged.
As such, there is a retractable speaker structure available in the market, in which a motor is adopted for driving a retracting mechanism to move, and a speaker is secured at an end section of the retracting mechanism and moved with the retracting mechanism, thereby allowing the speaker to be selectively protruded out or refracted in the panel or the vehicle door according to the actual needs.
However, the motor adopted in the above-mentioned retractable speaker structure is mostly a synchronizing motor, and the synchronizing motor has properties of constant sped, no need for speed adjustment and requiring a smaller starting torque, so the retractable speaker structure is required to be additionally installed with a reducing gear and a location sensor for adjusting the rotation speed of the retracting mechanism and limiting the stroke of the retracting mechanism, thereby causing the retractable speaker structure requiring complicated components and having relatively higher production cost.
In view of the above-mentioned shortages, the applicant of the present invention has devoted himself for inventing a novel design to solve the above-mentioned shortages.